The present invention relates to a jack, and more particularly to a pump lever for a jack.
FIG. 1 shows a floor jack having a lifting arm A, a cylinder C for driving said lifting arm A, a hydraulic pump P for driving said cylinder C, a plunger Pl for driving said hydraulic pump P, a sleeve S pivotally joined at the top end of said plunger Pl, and a handle H, one end of which is detachably received within said sleeve S. To raise the saddle of the lifting arm to its one upper position, it is necessary for one to laboriously squat on the ground and shake the handle H up and down. In addition, it is obvious that, in performing this operation, one usually applies force not only in raising but also in lowering the handle.
In FIG. 2, a pump lever for a jack therefore provided in U.S. Pat. No. 4,656,879 is shown. This pump lever has an elastic member E mounted between the sleeve and a limiting piece L secured to a base on the jack for guiding the sleeve as it is raised and lowered, so that the sleeve can be urged to raise to its uppermost position when a user frees the handle at a lowered position. However, this type of pump lever is difficult to assemble because the elastic force applied upon the sleeve and the limiting piece L biases them away from their proper positions in which the holes S1, E1, L1 respectively formed in the sleeve, the elastic member and the limiting piece, which are prepared to be passed through and joined by a pin G, are axially aligned with each other.